Prepare for threads. When preparing bat updates there are two important
things to protect - md->status MD_DIRTY bit and holes bitmap.
Use bat_lock to protect them.
https://virtuozzo.atlassian.net/browse/VSTOR-91821
Signed-off-by: Alexander Atanasov <alexander.atana...@virtuozzo.com>
---
drivers/md/dm-ploop-map.c | 83 ++++++++++++++++++++++++++++-----------
1 file changed, 61 insertions(+), 22 deletions(-)
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index bb15fa1f854b..0eaab61a0c31 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -555,13 +555,18 @@ static bool ploop_md_make_dirty(struct ploop
*ploop, struct md_page *md)
unsigned long flags;
bool new = false;
- spin_lock_irqsave(&ploop->bat_lock, flags);
+ /*
+ * Usual pattern is check for dirty, prepare bat update
+ * and then call make_dirty - to avoid races callers must lock
+ */
+
+ lockdep_assert_held(&ploop->bat_lock);
+
WARN_ON_ONCE(test_bit(MD_WRITEBACK, &md->status));
if (!test_and_set_bit(MD_DIRTY, &md->status)) {
llist_add((struct llist_node *)&md->wb_link,
&ploop->wb_batch_llist);
new = true;
}
- spin_unlock_irqrestore(&ploop->bat_lock, flags);
md->dirty_timeout = jiffies + ploop->md_submit_delay_ms*HZ/1000;
return new;
@@ -807,6 +812,8 @@ static void
ploop_advance_local_after_bat_wb(struct ploop *ploop,
dst_clu = piwb->kmpage;
+ /* holes bit map requires bat_lock */
+ spin_lock_irqsave(&ploop->bat_lock, flags);
spin_lock(&md->md_lock);
if (piwb->type == PIWB_TYPE_ALLOC)
goto skip_apply;
@@ -833,6 +840,7 @@ static void
ploop_advance_local_after_bat_wb(struct ploop *ploop,
clear_bit(MD_WRITEBACK, &md->status);
md->piwb = NULL;
spin_unlock(&md->md_lock);
+ spin_unlock_irqrestore(&ploop->bat_lock, flags);
wait_llist_pending = llist_del_all(&md->wait_llist);
if (wait_llist_pending) {
@@ -1077,10 +1085,22 @@ static int ploop_allocate_cluster(struct ploop
*ploop, u32 *dst_clu)
u32 clu_size = CLU_SIZE(ploop);
loff_t off, pos, end, old_size;
struct file *file = top->file;
+ unsigned long flags;
int ret;
- if (ploop_find_dst_clu_bit(ploop, dst_clu) < 0)
+ spin_lock_irqsave(&ploop->bat_lock, flags);
+ if (ploop_find_dst_clu_bit(ploop, dst_clu) < 0) {
+ spin_unlock_irqrestore(&ploop->bat_lock, flags);
return -EIO;
+ }
+ /*
+ * Mark clu as used. Find & clear bit must be locked,
+ * since this may be called from different threads.
+ * Note, that set_bit may be made from many places.
+ * We only care to clear what find got. parallel set is ok.
+ */
+ ploop_hole_clear_bit(*dst_clu, ploop);
+ spin_unlock_irqrestore(&ploop->bat_lock, flags);
pos = CLU_TO_POS(ploop, *dst_clu);
end = pos + clu_size;
@@ -1094,6 +1114,8 @@ static int ploop_allocate_cluster(struct ploop
*ploop, u32 *dst_clu)
else
ret = ploop_zero_range(file, pos, off - pos);
if (ret) {
+ ploop_hole_set_bit(*dst_clu, ploop);
+
if (ret != -EOPNOTSUPP)
PL_ERR("punch/zero area: %d", ret);
else if (ploop->falloc_new_clu)
@@ -1108,18 +1130,15 @@ static int ploop_allocate_cluster(struct ploop
*ploop, u32 *dst_clu)
if (end > old_size) {
ret = ploop_truncate_prealloc_safe(ploop, top, end, __func__);
- if (ret)
+ if (ret) {
+ ploop_hole_set_bit(*dst_clu, ploop);
return ret;
+ }
}
if (end > top->file_preallocated_area_start)
top->file_preallocated_area_start = end;
